Blog by Marc Brooker
Marc Brooker on distributed systems, databases and serverless.
4 posts in the last 90 days · newest 4 Oct
Strands Decider: Why Not an Encoder? Expertise level: exhausted. As I admitted in my last post, I am very much not an expert model developer. What follows is likely to be, at least partially, inaccurate. I have tried to be careful and quantitative, to partially balance a lack of…
Small Decisions: Engineering a Leading Model Or trying to, at least. Update: An evolved version of the model described here is now available as part of Strands. Check out strands-decider on github and HuggingFace. My day job has been primarily in AI for three years now, but I’d…
Lorenz and Little: How Much Does Your Tail Cost? Lorenz and Little sounds like hipster burger bar from 2015. It’s time for Marc’s Amateur Statistics Corner! Today: why I pay a lot of attention to tail latency when optimizing cost. I’ve written before on the importance of tail…
Aurora DSQL: Scalable, Multi-Region OLTP A paper! Our new paper, Aurora DSQL: Scalable, Multi-Region OLTP, is now available on Arxiv. I’m excited about this one: it’s a fully end-to-end look at how Aurora DSQL works, from query processing, to transactions, to replication, to the…
Meet Alice. Alice is impatient. What do you mean? Meet Alice. Alice uses your web service. Alice, like most humans, measures her time in seconds and minutes. Alice says your service is slow. You tell Alice that the mean request to your service completes in 100ms, but Alice says…
Is this blog written by AI? No. None of the human-readable text on this blog is written by AI, and I have no plans to change that. The weird grammar, incorrect assumptions, spelling errors, and annoying tics are all mine. Including the em dashes. I don’t use LLMs for writing. On…
Agentic software development hypothesis This is the quality content you come here for, right? Agentic Software Development Hypothesis: Weak form: Any coding task for which a complete specification is available will become trivial. Strong form: Any coding task for which a…
What’s Easy Now? What’s Hard Now? Take it easy. This is the fourth in a series about how AI is changing software development, after It’s time to be right., What about juniors?, and My heuristics are wrong. What now?. It stands alone, but if you found this interesting you may…
It’s time to be right. Outcomes continue to matter. Earlier this week, I spoke at AI Dev 26. This is what I spoke about there. I’ve been making money, in some form, building software for nearly 30 years. The last five months have been the most exciting of that entire time. I’m…
Spec Driven Development isn’t Waterfall Write down what you mean. After spending a few months writing (e.g. on the Kiro Blog), and speaking (e.g. Real Python Podcast, SE Radio) about spec-driven development, I’ve noticed a common misconception: spec driven development is a…
What about juniors? Start at the beginning. Last week I wrote about how the role of the most senior tech ICs has changed. Today, I wanted to share some thoughts on a more difficult topic: how the role of junior software engineers, folks just starting out on their career, has…
My heuristics are wrong. What now? More words. More meaning? Some people who ask me for advice get a lot of words in reply. Sometimes, those responses aren’t specific to my particular workplace, and so I share them here. In the past, I’ve written about echo chambers, writing…
Music To Build Agents By I don't have this problem, because I don't use a mouse. Press play, then start reading: Want to learn how to think about agent policy? Start with Goethe’s Der Zauberlehrling. So come along, you old broomstick! Dress yourself in rotten rags! You’ve long…
SFQ: Simple, Stateless, Stochastic Fairness Roll the dice. Paul E. McKenney’s 1990 paper Stochastic Fairness Queuing contains one of my favorite little algorithms for distributed systems. Stochastic Fairness Queuing is a way to stochastically isolate workloads from different…
You Are Here Where to next? The cost of turning written business logic into code has dropped to zero. Or, at best, near-zero. The cost of integrating services and libraries, the plumbing of the code world, has dropped to zero. Or, at best, near-zero. The cost of building…
Pass@k is Mostly Bunk Exponentially better results? I'll take three! Measuring the success of AI agents isn’t easy. It’s very sensitive to what success means, it can require a lot of samples, its highly context sensitive. Generally hard. So it doesn’t help that one of the most…
Agent Safety is a Box Keep a lid on it. Before we start, let’s cover some terms so we’re thinking about the same thing. This is a post about AI agents, which I’ll define (riffing off Simon Willison) as: An AI agent runs models and tools in a loop to achieve a goal. Here, goals…
On the success of ‘natural language programming’ Specifications, in plain speech. I believe that specification is the future of programming. Over the last four decades, we’ve seen the practice of building programs, and software systems grow closer and closer to the practice of…
What Does a Database for SSDs Look Like? Maybe not what you think. Over on X, Ben Dicken asked: What does a relational database designed specifically for local SSDs look like? Postgres, MySQL, SQLite and many others were invented in the 90s and 00s, the era of spinning disks. A…
What Now? Handling Errors in Large Systems More options means more choices. Cloudflare’s deep postmortem for their November 18 outage triggered a ton of online chatter about error handling, caused by a single line in the postmortem: .unwrap() If you’re not familiar with Rust…